How Does the Principle of Equivalence Lead to Gravity Curving Space?

[Dale]

can you tell me please one experiment
nobody could claim this . all the outer-space regions attained by people and their instruments are not of zero-gravitational field even if you were out of our solar system you are in gravitational field

So how far out do you believe we have to go until suddenly all of the laws of chemistry, quantum mechanics, electromagnetism, etc. fail?

Btw, this is definitely not supported by GR. GR asserts that the laws in zero gravity are locally the same as the laws in free-fall, it does not claim that in zero gravity all of the other laws cease to work.

I would like to remind you that this forum is not the place for speculation about personal theories. Please click on the Rules link at the top of the screen and review what you agreed to when you signed up.

 

[Mueiz]

Please don't play with words. Gravity ...




I've not read any of your ideas yet, but you can list them in a post briefly so I can decide whether they deserve to be given a shot or not by me!

AB

O.K. I promise you i will stop using the word gravity today forth ...
My opinion is that ;There are two Assumptions regarding the effect of acceleration on the geometry .one of them deals with gravitation this one is true and it is used in formulating GR so Will cause no problem .the second one deals with zero-gravity region this is incorrect and is not used in GR
so can not affect it ..but unfortunately - although not needed - is used by Einstein in rotating disc experiment to confirm the idea that acceleration changes geometry whither there is gravity or not .
one of my arguments is a paradox found in #47 and my reply to some objections in #80 i also hold the opinion that all reference frame in zero-gravitational field region are the same
because there is no a preferred frame in analogy to that free-falling frame found in the cases of gravitational field and by using the postulate of simplicity we have to choose flat geometry to be the geometry of all frames in such regions
I am looking forward to being given a shot by you

 

[Mueiz]

I would like to remind you that this forum is not the place for speculation about personal theories. Please click on the Rules link at the top of the screen and review what you agreed to when you signed up.

all theories of physics are personal ,there is no divine theory in science ...
If this forum is ask-and-answer ...pupil-and-teacher...i will not regret if the community
of the forum stop me

 

[Dale]

No, there are mainstream theories and there are personal theories. Yours here is personal, not mainstream, and is in direct opposition to GR.

So how far out do you believe we have to go until suddenly all of the laws of chemistry, quantum mechanics, electromagnetism, etc. fail?

 

[Altabeh]

No, there are mainstream theories and there are personal theories. Yours here is personal, not mainstream, and is in direct opposition to GR.

So how far out do you believe we have to go until suddenly all of the laws of chemistry, quantum mechanics, electromagnetism, etc. fail?

Yours are also personal and mind-made and above all else leaky because we have had nothing like zero-gravity until recently that this thread has been started! Please be patient and act scientifically! We can discuss these and convince the guy of his misunderstandings on the issue of gravity or whatever the problem is!

Thank you!
AB

 

[Dale]

We can discuss these and convince the guy of his misunderstandings on the issue of gravity or whatever the problem is!

You are more optimistic than I am.

 

[atyy]

Within GR, all matter fields (defined as fields with localizable stress-momentum-energy) require the metric for their definition.

In that sense, it is true that there is nothing without gravity.

 

[Mueiz]

So how far out do you believe we have to go until suddenly all of the laws of chemistry, quantum mechanics, electromagnetism, etc. fail?

Nowhere ... in fact.. even if we go to a place where there is no gravitation then our own masses will case gravitation to exist then affect the particles used for the study
this show the impossibility to study zero gravitational field experimentally
This is all i have ...i think it is of great benefit to open such dialogue between mainstream theories (found easily in textbook) and personal theories (scattered all over the world)
to improve our understanding of physics and our way of thinking
See you all rotating- disc followers in another thought fighting in another part of this forum may be quantum theory or the second law of thermodynamics

 

[Mueiz]

Within GR, all matter fields (defined as fields with localizable stress-momentum-energy) require the metric for their definition.

In that sense, it is true that there is nothing without gravity.

that is the true physics

 

[Altabeh]

Second observer in the edge of the disc ...then he is in uniform motion relative to the first observer(because the disc can be made large enough) so his frame is also inertial and he sees geometry as Euclidean

I try to proceed step by step to clear up any misunderstanding you have here and until the first problem is not solved, I won't keep going!

I think you could be smarter than Paul Ehrenfest but never can be as pedantic as John Stachel is! Even if the disc is very large, the rim is still a part of the disc which means that we are out of the zone! The special relativity holds only for inertial Lorentzian systems which always deal with the objects in the state of non-constrained motions! In contrary, constrained motions never allow you to have a pure inertia in the sense that,

1) Supposing there is no strong gravity to hold your shoes on disc, at each point along the circumference you may have a different angular velocity as recorded by the observer at rest and thus you gain a non-zero centrifugal acceleration! This is because your shoes have to be glued to the disc to remain on the disc so you're a part of the solid disc! This fallacy was made in the Ehrenfest's thought experiment which later was noticed by Stachel!

2) In case there is gravity and you're standing on the disc by gravitational force, you're no longer attached to disc and its enternal tensions won't affect your position (it seems like at quantum mechanical scales, the position of particles of disc are changing under your shoes). But in this case Lorentz contraction happens and the inert observer understands that the body of observer on disc shrinks so that using a simple calculation the result obtained by Einstein appears to be true, again!

Up to this point I can say that your thought experiment is fallacious! Do you have anything to say, now?

AB

 

[Mueiz]

I try to proceed step by step to clear up any misunderstanding you have here and until the first problem is not solved, I won't keep going!

I think you could be smarter than Paul Ehrenfest but never can be as pedantic as John Stachel is! Even if the disc is very large, the rim is still a part of the disc which means that we are out of the zone! The special relativity holds only for inertial Lorentzian systems which always deal with the objects in the state of non-constrained motions! In contrary, constrained motions never allow you to have a pure inertia in the sense that,

1) Supposing there is no strong gravity to hold your shoes on disc, at each point along the circumference you may have a different angular velocity as recorded by the observer at rest and thus you gain a non-zero centrifugal acceleration! This is because your shoes have to be glued to the disc to remain on the disc so you're a part of the solid disc! This fallacy was made in the Ehrenfest's thought experiment which later was noticed by Stachel!

2) In case there is gravity and you're standing on the disc by gravitational force, you're no longer attached to disc and its enternal tensions won't affect your position (it seems like at quantum mechanical scales, the position of particles of disc are changing under your shoes). But in this case Lorentz contraction happens and the inert observer understands that the body of observer on disc shrinks so that using a simple calculation the result obtained by Einstein appears to be true, again!

Up to this point I can say that your thought experiment is fallacious! Do you have anything to say, now?

AB

see my post # 80 and return back to me
i will continue discussing with you forever

 

[Dale]

Nowhere ... in fact.. even if we go to a place where there is no gravitation then our own masses will case gravitation to exist then affect the particles used for the study
this show the impossibility to study zero gravitational field experimentally

Then your objection in post 50 doesn't make any sense:

In your experiment you suppose that one observer can have zero acceleration and another one have non-zero acceleration in the absence of gravitational field

According to you even the miniscule mass of the accelerometers would create a gravitational field sufficient to result in exactly the behavior I suggested.

 

[Mueiz]

Then your objection in post 50 doesn't make any sense:



According to you even the miniscule mass of the accelerometers would create a gravitational field sufficient to result in exactly the behavior I suggested.

So the accelerometers is not able to study zero-gravitational field and this confirm what i and my friend atty said previously ; nothing exist in zero-gravitational field
if you use accelerometers or even thermometer you will be in gravitational field this fact with other facts made me say previously that the properties of zero-gravitational field is only attainable by pure intellectual principles

 

[Dale]

So the accelerometers is not able to study zero-gravitational field and this confirm what i and my friend atty said previously ; nothing exist in zero-gravitational field
if you use accelerometers or even thermometer you will be in gravitational field this fact with other facts made me say previously that the properties of zero-gravitational field is only attainable by pure intellectual principles

So why did you object to my post 49? What I described is perfectly correct even according to you.

 

[Mueiz]

So why did you object to my post 49? What I described is perfectly correct even according to you.

Because you use it to describe the properties of zero-gravitational field which is our topic and not the properties of the gravitational field of accelerometer which will affect the region in which we want to study the conduct of a particle
At that stage of discussion I would not talk about the problem of the gravitational field of the accelerometer because i was dealing with another incorrect assumption which is that objects can accelerate relative to each other in the absence of gravitational
It is acceptable method of argument that one leave incorrect point in a situation because he is dealing with another point which is independent

 

[Dale]

Because you use it to describe the properties of zero-gravitational field which is our topic and not the properties of the gravitational field of accelerometer which will affect the region in which we want to study the conduct of a particle

This is certainly not "our topic" it is only "your topic". You are the only person who is discussing zero gravitational field with your definition meaning absolutely no matter or energy anywhere in the universe. Everyone else was talking about the usual meaning of being far from any significant gravitational sources. I even specified "no significant gravitational sources" rather than zero gravity and yuiop used the clarifying phrase "zero gravitational field far from any significant gravitational sources" to make it clear what he meant.

At that stage of discussion I would not talk about the problem of the gravitational field of the accelerometer because i was dealing with another incorrect assumption which is that objects can accelerate relative to each other in the absence of gravitational

But again, your objection doesn't make any sense even within the framework you have stated here. First, you claim that the accelerometers won't work because they are in zero gravity. But if there is an accelerometer then by your definition there is a gravitational field. And so the accelerometers function exactly as I specified. So your whole objection saying that they wouldn't work that way is irrational and self-contradictory. You should have responded to my example by pointing out the gravitational field of the accelerometers. Given your definition that is the only correct response.

Also, your statement that a rocket engine in zero gravity would not burn is similarly nonsensical and self-contradictory. You claim that the rocket fuel won't burn because of the zero gravity and you also claim that there will be gravity because of the rocket. You should have responded to that by pointing out the gravitational field caused by the rocket, as it is your response is evasive and self-contradictory.

You have been very dishonest in this discussion. First, you take a non-standard position on the definition of an important term in the discussion. Then, when someone says something that clearly shows that they are using the standard definition you make an objection that on one hand is based on your non-standard definition and on the other hand is contradicted by that same definition. Then instead of clarifying your non-standard definition you spend several pages making similar self-contradictory statements.

 

[Altabeh]

This is certainly not "our topic" it is only "your topic". You are the only person who is discussing zero gravitational field with your definition meaning absolutely no matter or energy anywhere in the universe. Everyone else was talking about the usual meaning of being far from any significant gravitational sources. I even specified "no significant gravitational sources" rather than zero gravity and yuiop used the clarifying phrase "zero gravitational field far from any significant gravitational sources" to make it clear what he meant.

But again, your objection doesn't make any sense even within the framework you have stated here. First, you claim that the accelerometers won't work because they are in zero gravity. But if there is an accelerometer then by your definition there is a gravitational field. And so the accelerometers function exactly as I specified. So your whole objection saying that they wouldn't work that way is irrational and self-contradictory. You should have responded to my example by pointing out the gravitational field of the accelerometers. Given your definition that is the only correct response.

Also, your statement that a rocket engine in zero gravity would not burn is similarly nonsensical and self-contradictory. You claim that the rocket fuel won't burn because of the zero gravity and you also claim that there will be gravity because of the rocket. You should have responded to that by pointing out the gravitational field caused by the rocket, as it is your response is evasive and self-contradictory.

You have been very dishonest in this discussion. First, you take a non-standard position on the definition of an important term in the discussion. Then, when someone says something that clearly shows that they are using the standard definition you make an objection that on one hand is based on your non-standard definition and on the other hand is contradicted by that same definition. Then instead of clarifying your non-standard definition you spend several pages making similar self-contradictory statements.

Well this sounds logical to me! Even if we suppose Einstein's rotating disc was a failure, who says that acceleration means always a change in geometry? Yet the spacetime could be flat in the presence of accelerations and this has known examples in GR! Zero gravity doesn't exist and all Einstein wanted to show through his thought experiment was that if accelerations are present, then they possibly are in charge of a change in the geometry! This was just a motivation for Einstein to begin generalizing SR!

In his post # 80, Mueiz states that if Einstein was allowed to use locally the approximation I talked of in my earlier post, why wouldn't he be able to use this advantage and claim that the edge of disc is in a uniform motion?! Well if Mueiz was aware that he is making no sense out of such usage, then this would have ended right on page 4. Speaking of Einstein's motivation, if the ruler in the infinitesimally small distance ds of circumference of disc is to undergo Lorentz contraction, then it would change throughout the circumference even if the disc is constrained at its large scale because we look at the infinitesimally small line-element and then get to know how spacetime at large scale is curved around, say, Sun! But according to Mueiz's falsifying method (Mueiz's logic) since local flatness is guaranteed in a very small region, why not think of this globally? This is way beyond wrong!

AB

 

[Passionflower]

An accelerating disk in flat spacetime (assuming the disk has no mass) does obviously not change the geometry of spacetime, the spacetime remains flat.

One thing to realize is that if the disk is spun up and the radius remains the same the density of the material near the edges must be less than before the spinning or there are actually cracks.

 

[Mueiz]

Now I have a clear and simple method to show the Mistake of Rotating Disc Experiment
suppose we have two similar rotating discs that rotate around the same center at the same RPM
in opposite direction
The inertial observer is in the ground see both discs rotate
Now according to Einstein and many others..the geometry of each of the two discs is nonEuclidean...but ..they must take the same geometry because their relation to the inertial observer is quite the same.
But they are accelerating relative to each other
Acceleration and the same Geometry ?
Can DaleSpam , Altabeh ,Yoiup and Others resolve this simple paradox

 

[Mentz114]

Now I have a clear and simple method to show the Mistake of Rotating Disc Experiment
suppose we have two similar rotating discs that rotate around the same center at the same RPM
in opposite direction
The inertial observer is in the ground see both discs rotate
Now according to Einstein and many others..the geometry of each of the two discs is nonEuclidean...but ..they must take the same geometry because their relation to the inertial observer is quite the same.
But they are accelerating relative to each other
Acceleration and the same Geometry ?
Can DaleSpam , Altabeh ,Yoiup and Others resolve this simple paradox

What you are failing to understand is that the geometry as perceived by an observer riding on the disc is non-Euclidean.

In your eaxmple we can specify three observers A) not on a disc, not rotating B) riding on disc 1, C) riding on disc 2.

They all perceive different spatial geometry - there is no paradox.

Your arguments grow weaker and more childish - why don't you give up and stop wasting your time ?

 

[Dale]

suppose we have two similar rotating discs that rotate around the same center at the same RPM
in opposite direction
The inertial observer is in the ground see both discs rotate
Now according to Einstein and many others..the geometry of each of the two discs is nonEuclidean...but ..they must take the same geometry because their relation to the inertial observer is quite the same.
But they are accelerating relative to each other
Acceleration and the same Geometry ?
Can DaleSpam , Altabeh ,Yoiup and Others resolve this simple paradox

No, their relation to the inertial observer is opposite, one having the opposite angular momentum of the other. No paradox, just another installment of your usual disingenuous tactics, this one even less well-disguised than usual.

 

[Altabeh]

An accelerating disk in flat spacetime (assuming the disk has no mass) does obviously not change the geometry of spacetime, the spacetime remains flat.

Not from the perspective of the at-rest observer located outside the disc! Since in his eyes each ruler gets Lorentz contracted, then there must be more rulers when disc is in motion than when it is motionless to cover the edge of disc which is definitely a non-Euclidean result!

One thing to realize is that if the disk is spun up and the radius remains the same the density of the material near the edges must be less than before the spinning or there are actually cracks.

According to Stachel, this is wrong! The edge does not get contracted; it is, rather, the ruler that has a Lorentzian non-constrained motion! No cracks!

AB

 

[Altabeh]

No, their relation to the inertial observer is opposite, one having the opposite angular momentum of the other. No paradox, just another installment of your usual disingenuous tactics, this one even less well-disguised than usual.

Seconded by me as well!

AB

 

[Altabeh]

What you are failing to understand is that the geometry as perceived by an observer riding on the disc is non-Euclidean.

You mean that length contraction happens to exist from the perspective of observer riding on the disc? If so, then you're not correct!

AB

 

[Mueiz]

No, their relation to the inertial observer is opposite, one having the opposite angular momentum of the other. No paradox, just another installment of your usual disingenuous tactics, this one even less well-disguised than usual.

Also seconded By Altabeh
Ok ...then you see that the direction of rotating of the disc has something to do with the geometry in spite of the symmetry ... but if symmetry is not enough ...I have another thing which is that ..the direction of rotating of the disc can not affect the direction of acceleration which you claim to be the cause of nonEuclidean geometry

This is enough for me and am happy that I did not use any word against any user of this forum or its way of thinking except for those of science (incorrect,inconsistent,wrong,..etc) while receiving words like (absurd,speculation,home grown understanding,ridiculous misconception.. and many other)

 

[Dale]

the direction of rotating of the disc can not affect the direction of acceleration

This is certainly not correct. The direction of rotation most definitely does affect the direction of acceleration. The direction of acceleration for the two counter-rotating observers are 180° out of phase. They are most definitely not equal.

Are you going to continue to avoid discussing the fact that your previous objections to my accelerometer and rocket examples were wrong and my descriptions were completely accurate (even using your definitions)? You have no valid argument to stand on, despite more than 100 posts.

 

[Mueiz]

This is certainly not correct. The direction of rotation most definitely does affect the direction of acceleration. The direction of acceleration for the two counter-rotating observers are 180° out of phase. They are most definitely not equal.

Are you going to continue to avoid discussing the fact that your previous objections to my accelerometer and rocket examples were wrong and my descriptions were completely accurate (even using your definitions)? You have no valid argument to stand on, despite more than 100 posts.

The direction of any rotating object is always toward the center ..what you talked about is
the direction of motion ...this is a simple fact that I am sure you know it but may be just a mistake
Concerning the accelerometer an roket examples ... they are wrong if we neglect the gravitational field of the rocket and accelerometer as it was our method in that bost ... if you do not want to neglet it this will be new discussion but i agree with you concerning the effect of acceleration in gravitational field ( here i want to add that a particle can not be
affected by its own gravitational field but of course an experiment is not one particle ..there is observer and object ..in the example of rocket there is the rocket)

 

[Dale]

The direction of any rotating object is always toward the center ..what you talked about is
the direction of motion

I was talking about the acceleration, not velocity although it does apply to velocity as well. The acceleration, position, and velocity vectors are all 180° out of phase for the counter rotating observers. "Toward the center" is not a single direction, but many directions which change over time in a manner which is different for each of the two counter rotating observers.

Concerning the accelerometer an roket examples ... they are wrong if we neglect the gravitational field of the rocket and accelerometer

But your post 98 asserts that you cannot neglect gravitational field, your position in that post is that there is no gravitational field so small that it could be neglected. Therefore in the examples I gave the accelerometers and rocket would work as I stated, even according to your analysis. Or do you still assert that the rocket would not burn and if so on what justification?

 

[Mueiz]

I was talking about the acceleration, not velocity although it does apply to velocity as well. The acceleration, position, and velocity vectors are all 180° out of phase for the counter rotating observers. "Toward the center" is not a single direction, but many directions which change over time.

The fact that the direction of acceleration in rotating is toward the center can not be a topic of discussion (see any textbook in curcular motion ..but if you do not convinced I am ready to prove it)

But your post 98 asserts that you cannot neglect gravitational field, your position in that post is that there is no gravitational field so small that it could be neglected. Therefore in the examples I gave the accelerometers and rocket would work as I stated, even according to your analysis. Or do you still assert that the rocket would not burn and if so on what justification?

The two cases are different
The first one is Idealization Like that of( Ideal gas )something that does not exist but we can know its properties by theory (this is like accelerometer of zero mass to study
the properties of zero-gravitational region theoreticaly
The second one is Approximation something that does exist but you think that it can be teated like ideal case( this is when you want neglect the difference between zero-gravitational region and the region affected by the gravitational field of the accelerometer
In the first discussion I accepted the idealization and discuss with you the conduct of bodies in zero-gravitational field
In the second discussion I refused the approxmation when I said the fuel will not burn (in zero-gravitational field in idealization that the rocket is of zero-mass) but it will burn in the region affected by gravitational field of the rocket
in the true case

 

[Dale]

The fact that the direction of acceleration in rotating is toward the center can not be a topic of discussion (see any textbook in curcular motion ..but if you do not convinced I am ready to prove it)

Which direction is "toward the center"? Acceleration is a vector and vectors have a magnitude and a direction, so which direction is "towards the center"?

In the second discussion I refused the approxmation when I said the fuel will not burn ... but it will burn in the region affected by gravitational field of the rocket
in the true case

There, now was that so hard to finally admit?

And in the "true case" of the accelerometers/observers example of post 49?